1. Field of the Invention
The present invention relates to a process for preparing an inert organic solvent dispersion of an alkali hydroxide. More particularly, it relates to a process for preparing an inert organic solvent dispersion of fine alkali hydroxide particles having a diameter of order of m.mu. to .mu. such as 100 m.mu. to 500.mu..
The present invention also relates to a reaction using the same. More particularly, it relates to the reaction of an active methylene compound with an organoalkyl halide to produce methylene organoalkylated compounds useful as intermediates of agricultural chemicals and medicines. More particularly, it relates to a process for producing methylene organoalkylated compounds by reacting an active methylene compound with an organoalkyl halide in the presence of an alkali hydroxide.
2. Description of the Prior Arts
Heretofore, it has been difficult to obtain fine alkali hydroxide particles because of strong hygroscopic property of the alkali hydroxide.
On the other hand, an aqueous solution of a base such as alkali hydroxides or carbonates has been used for reactions of a halogenated compound with a compound having an activated hydrogen atom, such as a condensation reaction.
When an aqueous solution of a base is used for the condensation reaction such as dehydrohalogenation, the product may be decomposed because of the aqueous solution of a base.
In order to overcome the problem, it has been considered to use a solid base such as alkali hydroxides or carbonates. However, alkali hydroxides are hygroscopic and are insoluble in an inert organic solvents.
However, these conventional processes have various disadvantages and are not satisfactory process as the industrial process.
In the process (1), the condensing agent is remarkably reactive with water and accordingly, the activity of the condensing agent is decreased by the contamination of water to decrease the yield of the object compound. The explosive reaction may be caused by reacting the condensing agent with water to cause firing. Thus, the storage and maintenance of the starting materials and the operation for the reaction are quite difficult to be disadvantageous.
In the process (2), the expensive and water soluble aprotic polar solvent such as dimethylsulfoxide is used as the solvent. This is not easily recovered. Thus, it is disadvantageous from the economical viewpoint.
In the process (3), the expensive and water soluble quaternary ammonium salt is used as the catalyst. The discharge of the quaternary ammonium salt in a drainage can not be prevented whereby the nitrogen content in river, sea or lake is increased to cause the environmental pollution. Thus, it is disadvantageous from the economical viewpoint.
The inventors have studied to overcome these disadvantages of the conventional processes.
It has been well-known to produce methylene organoalkylated compounds by reacting an active methylene compound with an organoalkyl halide in the presence of an alkali hydroxide.
(1) The reaction is carried out in the presence of an alkali hydroxide (Organic Reactions Vo. 9, page 107).
(2) The reaction is carried out in a reaction medium of an aprotic polar solvent such as dimethylsulfoxide (J. Org. Chem. Vol. 34, pages 226, 1969).
(3) The reaction is carried out in the presence of a catalyst of a quaternary ammonium salt (Acta. Chem. Scand. Vol. 23, page 2204, 1969; Tetrahedron Lett. Vol. 15, 1273, 1973; Tetrahedron Vol. 32, page 2235, 1976).
One of the important examples of the reaction of the active methylene compound with an organoalkyl halide is the production of .alpha.-isopropyl halophenylacetonitrile.
(1) The reaction is carried out in the presence of a condensing agent such as alkali metals, alkali metal alcoholates, alkali metal halides or alkali metal amides (Japanese Unexamined Patent Publication No. 5350/1975).
(2) The reaction is carried out in the presence of a condensing agent of an alkali hydroxide in a medium of an aprotic polar solvent such as dimethylsulfoxide and dimethylformamide (Japanese Unexamined Patent Publication No. 154217/1975).
(3) The reaction is carried out in the presence of a condensing agent of an alkali hydroxide and a catalyst of a quaternary ammonium salt (Japanese Unexamined patent Publication No. 63145/1976).